Psyc 412 1st Edition Lecture 12Outline of Last Lecture SNOW DAY CLASS CANCELLEDOutline of Current Lecture I. Significance of PainII. Elusive Nature of PainIII. Pain management IV. Pain perceptionCurrent Lecture- The Significance of Paino Some pain is critical for survival. medical consequences: pain is the symptom most likely to lead an individual to seek treatmento medically significant: pain can be a source of misunderstanding between a patient and the medical providero Pain has a survival function Leprosy: suffer nerve damage and become insensitive to pain; they do a lot of damage to their bodieso Sometimes the pain doesn’t go away even after injury has been healedo Source of friction between patient and doctors Doctor can’t determine what patient’s pain level is-pain killers aren’t always prescribed (can be addictive) Some people with chronic pain go to doctor not for the pain but to get the drugso Doctors don’t have an objective way to measure paino Lower back pain-very commono Pain is prevalent and costly in the U.S. ~ 30 billion spento Psychological significance: depression and anxiety worsen the experience of paino Pain is very prevalent and costly in the U.S. and around the worldo “pain cycle” Pain-withdrawal-depression-fatigue Depression increases pain- The Elusive Nature of Paino pain is a psychological experienceo pain is influenced by the context in which it is experiencedo pain has a cultural componento Marathons-long distance runners: have significant amounts of pain, but are not as distressed because they know the pain will stop at some point Know pain is a product of pushing their bodieso Different languages describe pain differentlyo Measuring pain: verbal reports pain behavior:- behavior that arises as a manifestation of chronic pain- assesses how pain has disrupted the lives of patientso Usually have to rely on what the patient says about pain (verbal reports)o Pain behavior: Behaviors that show pain: limping, crying, groaning How has their life changed because of pain: spending less time with family, working less, less enjoymento PBS video: Healthy Body Healthy Mind Chronic pain and techniques/methods to overcome ito Physiology of pain: overview:- pain is a protective mechanism- pain is accompanied by motivational and behavioral responses Sometimes the responses to pain cause more problems (compensatory behaviors) Hard to focus on other things when in pain- Hard to be nice, more irritable- Motivation decreases- Hard to sleep- Pain management center will give a very detailed pain reporto Pain feels different sometimes-activity of different nerve fiberso Emotional effects- Experimental technique for measuring paino Used fMRI techniques to isolate a “pain signature” of activation in specific brain regionso >90% accuracy in distinguishing pain from other forms of stimuli, recall of pain, or anticipation of paino Were able to see areas of the brain that only lit up for thermal pain, no other types of pain- three kinds of pain perception:o mechanical nociception: mechanical damage to body tissueo thermal damage: damage due to temperature exposureo polymodal nociception: pain triggers chemical reactions from tissue damageo Nociceptors are nerve cells specialized to detect particular types of (painful) stimulio Greater concentration on some areas of the body (hands, feet, lips)- two major types of peripheral nerve fibers involved in paino A-delta fibers: small, myelinated fibers that transmit sharp paino C-fibers: unmyelinated fibers that transmit dull, aching paino several other areas of the brain also involved in the modulation of paino Brain areas: periductal gray: area that produces endorphins endorphins: dull pain opioids mimic endorphins- If the pain is strong enough, the body (spinal cord) will automatically move the body before the signal is sent to the brain (spinal reflex)- Neurochemical bases of pain and its inhibition:o landmark study: D. V. Reynolds 1969o SPA: Stimulation-Produced Analgesia- Akil, Mayer, and Liebeskind (1972, 1976)o three families of endogenous opioid peptides Beta-endorphins: limbic system, brain stem Proenkephalin: throughout CNS Prodynorphins: gut, posterior pituitary, brain- Rat study: could do surgery on rats without pain because blocked certain areas of brain- Stress-induced